Whether or not you should be taking a lipid-lowering medication depends on your risk of a heart attack and your LDL cholesterol level. 
People at higher risk for a heart attack begin taking medication at lower LDL cholesterol levels.
The primary goal of taking a lipid-lowering medication is to lower LDL cholesterol. A large number of randomized, controlled trials clearly show the benefits of reducing LDL cholesterol with medication. In the Heart Protection Study, for instance, taking a lipid-lowering statin reduced the risk of heart attacks and strokes by about one quarter to one third. A statin was effective not only in people with existing heart disease but also in men and women at high risk for a heart attack, including those with diabetes, peripheral arterial disease (narrowing of arteries in the legs), or a history of stroke. In addition, even people with pretreatment LDL cholesterol levels of less than 100 mg/dL benefited from statin therapy.
Despite these advantages, studies show that as many as half of individuals prescribed lipid-lowering medications stop taking them after one year, even though these drugs should be continued indefinitely. Additionally, many people taking lipid-lowering medication are on too low a dosage to achieve an adequate reduction of their LDL cholesterol levels.
Your doctor can choose from a number of drugs to help lower your LDL cholesterol. Statins are the most commonly prescribed. If taking a statin does not lower your LDL cholesterol enough, your doctor may add another cholesterol-lowering drug such as a bile acid sequestrant or a cholesterol absorption inhibitor. Statins can also lower triglyceride levels and increase HDL cholesterol levels. But if your triglycerides are extremely high, your doctor may prescribe a fibrate or a medication called Lovaza (omega-3-acid ethyl esters). Similarly, if lifestyle measures and a statin have not increased your HDL levels sufficiently, a lipid-lowering drug called niacin may help boost your levels.
Get more detail on the six classes of lipid-lowering drugs:
